Asymmetric Exhaustive Service Polling System with Bernoulli Feedback

This paper studies asymmetric exhaustive service polling system with Bernoulli feedback,gives the distributions of queue lengths and sojoun times,and obtains some other results,in stationary condition.     

Service Gated Discrete-time Polling System with Bernoulli Feedback

This paper analyzes asymmetric limited gated service polling system with Bernoulli feedback. By the imbedded Markov chain theory and the probability generating function method,The authors derive the generating function of intervisit time , polling cycle time , service time of each station and queue length in the each station .Furthermore , the successive sojourn time of customer C in ith station (i=1,2,...N) and queue length after the (m-1)th service are obtained.     

Queue Length in the Gated Service and Limited Service Polling Systems with Bernoulli Feedback

In this paper,we consider the gated service polling system and the limited service polling system for non symmetrical stations with Bernoulli feedback,give the distributions and the first moments of queue lengths and some other results.     

P2P网络中保证瓶颈带宽公平性的路由队列管理

在基于域结构的P2P计算网络环境下,针对RED(Random Early Detection)队列管理机制不能完全保证各流量公平共享瓶颈带宽进行改进,运用窗口滑动技术,根据网络流量状态,动态地设置阈值参数mint,maxt和maxp,使队列变化随网络流量变化动态调整,实现了一种Optimized-RED队列管理机制.仿真分析表明:Optimized_RED队列管理机制能有效地保证各连接流量公平共享网络瓶颈带宽,平滑网络瓶颈的阵发流.     

桥梁两端交叉口不同控制方式效果的比较

以福清市玉融大桥及两侧桥头交叉口为研究对象,以桥面进口道上的95%排队长度和平均区间速度为交通效益的目标评价指标,应用Synchro和Vissim仿真优化软件对无信号控制、单点优化信号控制和协调优化控制系统进行设计优化及评价.结果表明:采用协调优化控制系统和单点优化信号控制系统后,95%排队长度分别比无信号控制减少了52.00%和49.85%,平均区间速度分别提高了30.78%和7.5%.由此可知,信号协调优化控制系统是比较理想的控制方式.     

农村区域经济层次划分方法的研究

探讨了农村区域经济层次划分的方法,确立了有关指标体系,建立了方法模型,并进行了聚类分析和综合指标排序,最后就这种方法的应用进行了实证分析。     

网络拥塞控制策略研究

研究了传统的网络拥塞控制策略DropTail的算法原理,依据实验结果,说明DropTail算法存在死锁、满队列、全局同步等问题。提出了一种新的RED算法,RED算法可有效地避免系统出现TCP流全局同步现象,提高了网络利用率和系统的鲁棒性,更能适应网络流量的变化,获得较为稳定和优异的性能。本研究成果为进一步研究ARED和AQM算法提供了重要依据。     

基于交通波理论的高速公路瓶颈路段排队分析

近年来内蒙古煤炭经济发展迅速,但与此同时煤炭运输也造成了严重的交通拥堵.本文通过对G6高速公路呼和浩特至集宁段的交通量、车速等数据的统计,结合呼集高速公路线形结构,采用交通波理论对比分析重载车辆和标准车辆在瓶颈路段的集结——消散过程.分析结果表明重载车辆排队消散时间和排队长度过长,平均分别为标准车辆的3.45倍和13.43倍,最大分别为标准车辆的3.97倍和15.26倍.因此,在今后设计重载车辆较多的道路时,要尽量减少大的线形突变.     

Message-importance aware adaptive queue management mechanism in opportunistic networks

The network resources are limited in opportunistic networks. For improving the effectiveness of nodes’ storage resources, this paper proposes a proper method to estimate node’s activity degree. Based on the node’s activity degree, we estimate the messages’ importance degree, and then design a message importance degree aware adaptive queue management mechanism (MAQM) by the importance of message. This mechanism estimate node’s activity degree by its meeting times with other nodes, and estimate messages’ importance degree by node’s activity degree .Simulation results show that the method to evaluate node’s activity degree is accurate.Deviation is less than 5%. Tompared with other cache management mechanisms, MAQM can improve message delivery rate effectively, while reducing latency and overhead ratio.     

Improved DDR algorithm in media stream scheduling

Fuzzy control variable weight method of multi-factor decision-making adaptive deficit round robin scheduling algorithm (VWADRR), an improved deficit round robin(DRR) scheduling algorithm is put forward. It’s used in the circumstance of scheduling multiple multi-media data streams. It bases on multi-factor decision-making in the fuzzy control theory, specific to the use of the variable weight method. It’s adaptive for output channel bandwidth and buffer size of each input queues. Variable weight method makes decisions based on these two factors, that is, to determine the QN as variable in DRR. Considering the time of each packet sent, it reduces the packet delay. It effective uses buffers and bandwidth in the heavy network traffic situation, significantly reduces the possibility of buffer depletion, also smoothes burst.